Astrocytic Function

Astrocytic function encompasses the diverse physiological roles played by astrocytes in maintaining CNS homeostasis, supporting neuronal networks, and coordinating brain metabolism and blood flow.

• Neurotransmitter regulation:
  1. Uptake of glutamate via EAAT1/2 to prevent excitotoxicity.
  2. GABA and adenosine recycling.
• Ion buffering:
  1. K⁺ spatial buffering during neuronal activity.
• Neurovascular coupling (NVC):
  1. Astrocytic endfeet detect synaptic activity and signal to nearby blood vessels.
• Energy metabolism:
  1. Lactate production and shuttling to neurons (astrocyte-neuron lactate shuttle).
• Synaptic modulation:
  1. Tripartite synapse: astrocytes modulate synaptic strength and plasticity.
• Water homeostasis:
  1. Regulation through AQP4 in astrocytic endfeet.
• Blood-brain barrier (BBB) support:
  1. Structural and paracrine support for endothelial tight junctions.

• Astrocyte function varies by brain region, age, and reactive state.
• In early postnatal stages (e.g., P8), astrocytes show heightened plasticity and involvement in NVC development.
• Expression of key molecules (e.g., SorCS2, AQP4) can be developmentally regulated.

• Excitotoxicity due to failed glutamate clearance.
• Impaired NVC and brain perfusion.
• Edema from disrupted AQP4 localization or function.
• Neuroinflammation and glial scarring (reactive astrogliosis).
• Contribution to neurodegenerative diseases and epileptogenesis.

• astrocyte_dysfunction
• neurovascular_coupling
• glutamatergic_neurotransmission
• AQP4
• SorCS2
• tripartite_synapse
• reactive_astrogliosis